Explosively driven stud with split shank locking means



A. T. MASTERS EXPLOSIVELY DRIVEN STUD WITH SPLIT SHANK LOCKING MEANS Filed Dec. 23, 1953 Aug. 11, 1959 2 Sheets-Sheet 1 FIG.3

INVENTOR. ALBERT T MASTERS lain lull 1 ATTORNEY 1959 A. T. MASTERS 2,898,964

EXPLOSIVEIQY DRIVEN s'run WITH SPLIT SHANK LOCKING MEANS Filed Dec. 23. 1953 2 She etsSheet 2 FIG. 5 22 (2? 2| I8 2o '9 K Y H H I IN V EN TOR.

ATTORNEY "EXPLOSIVEILY DRIVEN STUDWITH SPLI'I "LOCKING MEANS Albert '1. Masters, 'Fairview .Park, {)liio, assignor, hy

mesne iassignments, to Olin Mathieson Chemical Cornporation, -a corporation of Virginia Application December '23, 1955,Ser'ialNo. 4011;049

2 Claims. (Cl. '151-41.7

E-Patent No. .1 ,365 ,8'69 into the 'sur face of some building :materials for supportingwork objects thereon, it has been .found that asatisfactory hold is not-obtainedon account rat @the relatively :porous and soft nature of these building materials -:especia1ly certain lightly aggregated pre-cast ibuilding blocks. Furthermore, the presence in"suh=materials of voids, some unusually large, distributed at random .gives thematerials an unpredictably variable "e ifective thickness from point to point less than the apparent measurable thickness. This unexpected lesser real thicknessis responsible :for the occasional and undesired 'passage of an explosive driven stud through the material.

It is, therefore, one of the objects of this "invention provide studs of the type described having improved holding power in :all materials and especially in those in whichonly a poor hold has been heretofore attainable :by this type of fastener. Another "objectistheprovision --of an 1 explosive driven stud capable ofsubstantially resisting the dangerous tendency to completely fly through materials having many voids therein.

These and other objects and advantages, which will becomeapparent from the'descrip'ti'onin detail'of various specific embodiments which follows, are obtained in accordanee with this invention by provision of a's'tud having a portion of the shank so constructed 'as to "be adapted when driven to exert pressure transversely to the axis of the'stud shank to not only'betterisecurethe stud inthe material into which it has been projected from an explosive operated tool but to also resist vunexpectedly easy passage through materials characterized 'by voids. The stud has a solid front or point portion for penetrating the material into Whih it is fired and for making in the material a hole closely fitting about the shank and also has a divided, parted or furcated ,portion of the shank 'back ofth'e front portion adapted "to follow into the hole formed and there exert lateral pressure and whenever possible to undergo lateral deformation. The latter portion or compression grip portionof the shank is generally :abifurcated section and preferably resilient. To further enhance the grip obtained, the surfaces of the ,pressure exerting deformable part :of the shank :may be irough'ened in such a way -:as to have laterally and reanwardly directed barbs.

Patented Aug. 11, 1959 "-erally on'the material into whitih the fastener'isdrive'n.

In operation the spring-like portion tends to 'secur'e'itli'e fastener in the material by the pressure "it exerts upon the sidewalls of "the "cavity 'formc'il'inthe material by the "fastener.

However, the invention will beb'ett'er understood from the following description of several preferred specific embodiments with reference to the drawingin which:

Figure lvis a side elevational view of one-embodiment "of'th'e invention;

Figure 2 is a cross sectional view taken on line II1 I of Figure 1;

Figure 3is a side elevational view partly in cross "section showing the fastenerof the embodiment of Figures '1 and 2 'turned9'0 about its axis and driven into an object;

Figure '4 is a side elevational view of another embodimerit taken a'fter'the stud has 'been rotated through 9'0 about its axis as compared to the view of'Figure 1;

Figure 5 is a=side elevational view of another embodi- .ment of this invention;

h Figure -6 is aside elevational view partlyzin cross section'showing the fastener of Figure -5 after it has been driven;

Figure MS a side elevational view of a further embodim'ent;and

.Figure 8 is a side elevational view of a still further embodiment shown driven and connected to a load 'support.

In the embodiment ofFigures 1, 2'and 3 the stud consists imgeneralof-a shank l and anenlar ged holding head .portion 2 the latter of which has a [diameter islightlyless than that of the bore of the barrel 1-2 of the driving teal. The shank :1 has a-front portion 3 consisting of a solid penetratingmoint. The forepart of the shank 1 back of portion 3 is :a split or "bifurcated section consisting of a medial :or axial,part 4 in=the:shank -1 'and connecting ,=porti'ons or branches 5 and -6 of semicircular cross section as resilient continuations *of the shank between the front :sectionfi and the rear ;part of the =shank "adjacent the head 2. As is more clearlyshown in Figure 2 the =branches -5 zand fi are contiguous eat ithe ,plane of the separation 4 but are translated parallel to ithat plane -'so that :5 and '6 :are oifset or displaced laterally outwardly with respect to each other to an overall :exten't almost equal to the diameter of the head 2. The lateral displacement and .resilience 'of the branches 5 and "6 always imparts to the .fastener when driven a compression grip. The partial division :of the shank 1 along a plane vat 4 includes the centefline of the shank 1. The sections :5 and i6, which "in the ease of a circular shank are semicircular, are then deformedtoanoveevereaeh otherratlright 'angre's to-thecenterline in such a manner that the maximum lat- -'eral displa c'e'men't takes place at a po'in't about halfway between the ends of the separation 4 while the "ends 6f these-sections "merge progressively *into line with the from: and r'ear parts of the shank 1. When'the fastener is driven from the barrel 12 of a suitable tool, Figure '"3, through washer 11 so as to pierce supported object 10 and the 'supportingmateria1 '9, the hole formed material 9 by 3 the point 3 compresses resilient branch sections 5 and 6 toward the centerline of the shank 1. The sections 5 and 6 in turn tend to assume the positions 7 and 8 shown in dashed lines. As a result the offset branches 5 and 6 of the split section of the shank exert a compression grip on the material 9. Such degree of ultimate lateral deformation of sections 5 and 6 as does take place further assists in maintaining the stud of this embodiment in driven position. To enhance the grip obtained each of the olfset sections 5 and 6 may be provided with rearwardly projecting barbs at the laterally projecting edges.

The embodiment of Figure 4 like'the previous embodi- .ment has a shank 13, a solid penetrating front end 14 and a rear end portion 15 of enlarged diameter as compared to the shank 13 and threaded for admission of a nut.

The split section of the shank likewise consists of the laterally offset contiguous resilient half-sections 16 and 17 with this difference, however, that the degree of displacement is greater and laterally 16 and 17 extend slightly beyond the enlarged rear end 15. The advantage of this is twofold. In the first place and particularly when 16 and 17 have heavy spring properties, in this way the greatest compression grip is obtainable. Secondly, as this stud is fed into the breech of an explosive operated tool, bowed sections 16 and 17 help tohold the stud in the barrel until it is fired.

Where the threaded rear end of the stud is not enlarged but instead is of the same diameter as the shank,

and 23 have been formed so as to tend to assume a laterally most severely bowed position. Since such posi- 'tion would interfere with loading of the stud into the bore of the barrel of the driving tool, this stud is further provided with a thin sleeve member 24 encircling the stud about midway at sections 22 and 23 so as to hold them straight and unbowed before the driving operation.

'To hold sleeve 24 thus positioned during firing a slight circumferential enlargement or knurl 25 is provided about the forepart of split shank sections 22 and 23. As the stud is driven into a supporting material 27, Figure 6,

on which an object 26 is held with the aid of nut 28 'threaded on the rear end 20 of the stud, sleeve 24 is stripped back along shank 18 thus freeing compression spring sections 22 and 23 for exertion of lateral compressive forces on material 27.

The embodiment of Figure 7 is a stud having an enlarged head 30 and a reduced shank 28 with the solid penetrating front section 29. Back of section 29 the shank is separated longitudinally and inwardly at two diametrically opposed points so as to produce the outwardly and rearwardly projecting parts 31 and 32. These not only provide a compression grip but also operate as barbs for resisting withdrawal of the stud.

Another form which the invention may take is illus- "trated in Figure 8 where the stud shown after driving in- .to material 42 comprises a solid pointed penetrating front end 33, the shank 34 and the threaded rear end 35.

'Shank 34 is diametrically separated at 36 so as to provide resilient compression members 37 and 38, which are formed so as to tend to bow out laterally in a direction normal to the plane of the part 36 in spaced apart position except at the ends of the division 36. Member 37 is further provided with a cut at an angle to produce out- ;wardly rearwardly directed auxiliary grip member 39 and similarly bowed member 38 is provided with auxiliary member 40. The stud also includes retaining collar 41 initially positioned about members 37 and 38 so as to .hold them in contiguity and substantially straight with the rest of shank 34 before the stud is driven into the material 42 after which collar 41 is stripped back as ,shown by material 42 during penetration to unsheath and release compression members 37 and38 and permit auxiliary members 39 and 40 to open out completely to the extent permitted by the softness and proximate voids of material 42. As a load is applied to the stud through any suitable connection means 43, auxiliary members 39 and 40 come into play as more effective and positive holding means together with the compression grip provided by members 37 and 38 to wedge the shank 34 in place.

While the various embodiments illustrated in the drawing and herein described have resilient compression members, it is to be understood that deformation of these members outwardly against the resilient forces under driving forces as well as the resilient force is made use of particularly in material having voids. Lateral expansion of thecompression grip members serves not only to improve the grip of the explosive driven studs of this invention but to increase the resistance to penetration in proportion to the number and size of the voids encountered in the load supporting or target material during penetration. It is this feature that reduces the likelihood of the stud being fired completely through and beyond the support material.

While the invention has been described with respect to specific embodiments now believed preferred, it is to be understood that changes and modifications may occur to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

What is claimed is: 1. An anchoring stud adapted to be forcibly projected from the bore of the barrel of an explosive actuated stud driving tool into a base material and comprising an elongated circularly cylindrical shank having a solid elongated oglvally pointed front end portion adapted to penetrate said material and form a stud-retaining hole therein Without disruption of said portion, said shank having a rear end portion for fastening members to said base material tegral segments tending to assume a laterally bowed posi- ,tion in said material whereby saidstud is more securely held in said material, and annular centering means snugly enclrchng 881d spht portion frictionally retained and slidably mounted thereon for preventing excessive and premature lateral bowing of said portion until said stud has penetrated the base material and caused said encircling means to be stripped back from said split portion, said shank having a diameter substantially less than that of said bore, both of said encircling means and rear end portion being of an outer diameter substantially equal to but shdably fitting that of said barrel bore, whereby said stud may be readily inserted into said bore preparatory to drivlng and maintained therein in substantial axial until driven.

2. An anchoring stud adapted to be forcibly projected from the bore of the barrel of an explosive actuated stud drivlng tool into a supporting base material and comprising an elongated circularly cylindrical shank having a solid elongated ogivally pointed front end portion adapted to penetrate said material and form a stud-retaining hole therein without disruption of said portion, said shank having a threaded rear end portion for fastening members to said base material and also having a split portion ad acent said front end adapted to undergo lateral expansion upon penetration of said front end portion, said split portion including integral segments tending to assume a laterally bowed position in said material whereby said stud is more securely held in said material, and a thin relatively elongated circular sleeve snugly encircling said split portion and slidably retained thereon for preventing bowing of said contiguous segments until said stud has penetrated the base material and caused said sleeve to be stripped back from said split portion, all of said shank being of a diameter substantially less than that of said barrel bore, and said shank including at least one protrusion ahead of said split portion to restrain said sleeve against movement forwardly during the driving operation and prior to penetration of the split portion into the base material, said sleeve having an outer diameter substantially equal to but slidably fitting that of said bore.

References Cited in the file of this patent UNITED STATES PATENTS ONeill June 16, 1914 10 Horton Apr. 17, 1917 

